Valves are used to control gases or other fluids in various types of apparatus and vehicles, such as aircraft. For example, valves may be used to control the supply of bleed air to aircraft anti-icing systems, among various other uses in aircraft and other types of apparatus and vehicles. In the aircraft anti-icing system example, valves are typically configured to open automatically via a mechanism such as a spring, and to close automatically through a pneumatic mechanism. However, in some instances, it may be desirable to include an alternative mechanism, such as a manual mechanism, for opening a valve in the highly unlikely event that a valve spring, or some other part, does not function properly. It is also desirable for such a manual mechanism to be able to lock the valve in a full-open position, and for pilots of aircraft, or operators of other vehicles or apparatus, to be able to visually verify that the valve is locked in the full-open position. Moreover, because valves used in aircraft can be subjected to potentially severe temperatures and conditions, it is desirable that such valves are designed to withstand such temperatures and conditions.
Accordingly, there is a need for a valve assembly, capable of withstanding potentially severe temperatures and conditions, for opening a valve, locking the valve in an open position, and providing visual confirmation of the same to the operators of the vehicle or apparatus.